A key sentence:

"Consistent with the law, the Office will not knowingly register works produced by a machine or mere mechanical process that operates randomly or automatically without sufficient creative input or intervention from a human author."

The "produced by a machine or a mere mechanical process" part seems uninteresting; the actual criterion is "without sufficient creative input or intervention from a human author". What is sufficient? I may have to read in more detail to see if this is any more than an "I know it when I see it...".